Finding a C1 Function for Continuous f,g in Real Numbers

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SUMMARY

The discussion centers on the existence of a continuously differentiable (C1) function h defined on R2 \ { (0,0) } that satisfies h(x,y) = r(x,y) on the set A and h(x,y) = s(x,y) on the set B, where A and B are defined based on two continuous functions f and g. The condition f(x) < g(x) for all x ≠ 0 and f(0) = g(0) is crucial for the formulation. The solution involves the application of partitions of unity, which allows for the construction of the desired function h.

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johnson12
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Hello,I need some advice on a problem.

Let f,g:R\rightarrow R (where R denotes the real numbers) be two continuous functions, assume that f(x) &lt; g(x) \forall x \neq 0 ,

and f(0) = g(0).Define A = \left\{(x,y)\neq (0,0): y&lt; f(x),x \in R\right\}<br />

B = \left\{(x,y)\neq (0,0): y&gt; g(x),x \in R\right\}<br />Let r,s:R^{2}\rightarrow R be C^{1},and show that there is a C^{1} function h defined on

R^{2}- \left\{(0,0)\right\} such that h(x,y) = r(x,y) on A and h(x,y) = s(x,y) on B.

It seems that this follows from partitions of unity, but I am not sure where to
start, any suggestions at all are helpful.
Thanks.
 
Last edited:
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johnson12 said:
Hello,I need some advice on a problem.

Let f,g:R\rightarrow R (where R denotes the real numbers) be two continuous functions, assume that f(x) &lt; g(x) \forall x \neq 0 ,

and f(0) = g(0).Define A = \left\{(x,y)\neq (0,0): y&lt; f(x),x \in R\right\}<br />

B = \left\{(x,y)\neq (0,0): y&gt; g(x),x \in R\right\}<br />


Let r,s:R^{2}\rightarrow R be C^{1},and show that there is a C^{1} function h defined on

R^{2}- \left\{(0,0)\right\} such that h(x,y) = r(x,y) on A and h(x,y) = s(x,y) on B.

It seems that this follows from partitions of unity, but I am not sure where to
start, any suggestions at all are helpful.
Thanks.

UPDATE: PROBLEM SOLVED
 

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